Month: September 2014

The goldenrod is making a fantastic display this fall in my prairie and other unmown areas. I love watching the waves of gold sway on a sunny fall day.

Goldenrod (Solidago sp.) thrives in sun to part sun and is a deer-resistant perennial. There are thirty different types of goldenrod that grow in Illinois. They range from the three foot to seven foot tall. Each has a cluster of bright yellow flowers at the top and sides of stems.

There are also some cultivated goldenrod varieties that do well in flower gardens. Retired horticulture educator Nancy Pollard described the flowers as “stunning” when paired with blue and purple New England asters. Her great performers include:
• Solidago flexicaulis ‘Variegata’: with variegated foliage it brightens semi-shaded wooded areas. This goldenrod is over 4 feet tall and has a spreading nature. It blooms from early September to mid-October.
• Solidago rugosa ‘Fireworks’ has graceful fine textured foliage with arching branches. The stems of the golden blooms arch in many directions like fireworks. It grows three to 4 feet tall. It tolerates wet soil and grows slowly by underground rhizomes but generally doesn’t get out of hand. It blooms mid-September to late October.
• Solidago sphacelata ‘Golden Fleece,’ which has pyramidal densely flowering stems that form a compact groundcover, grows to 18 to 36 inches depending on site conditions. It is drought tolerant and is also good for fall container gardens. September flowers attract hummingbirds, bees, and butterflies.

An added bonus is that goldenrod and other fall blooming flowers are also good at supporting our native wildlife. “Native wildflowers and their cultivars—yellow goldenrod, purple asters, golden sunflowers, and dusty rose Joe Pye—create a lot of interest not only because of the attractive flowers but also for the amazing variety of native butterflies, moths, and other insects that feed on them,” said Nancy Pollard.

“Fall wildflowers are particularly outstanding at attracting adult moths and butterflies, which lay eggs that hatch into larva (caterpillars). The larvae provide a high-protein source of food for many birds, particularly warblers and neo-tropical migrant birds of conservation concern. Birds are very good at keeping populations of these insects in check so it is a very good situation for all,” Pollard explained.

Unfortunately goldenrod can cause allergy symptoms in some people. According to Thomas Leo Ogren in his book “Allergy-Free Gardening” about thirty percent of those allergic to ragweed are also allergic to goldenrod. Luckily goldenrod pollen is heavier and less likely to become airborne than ragweed pollen.

Take a walk among a field of goldenrod this fall and experience the wonders of nature all around you.

Start next year’s flower display this fall. Rhonda Ferree, Horticulture Educator with University of Illinois Extension, says that now is the time to set out the spring flowering bulbs. It seems like a lot of work now, but after the long winter you will really enjoy those blooms. In addition to the standards such as tulips and daffodils, try some of the other small flowering bulbs. For example, anemones, snowdrops, and winter aconite all bloom very early and have especially beautiful flowers. Snowdrops are among the smallest and daintiest of the spring-flowering bulbs and often flower in early March, before all the snow has gone.

Bulbs can be planted in perennial borders, rock gardens, or naturalized in the lawn and wild flower garden. They are grown for beauty, fragrance, cut flower use, or combinations of these. The informal growth of plants such as daffodils adapts well to naturalized plantings, but also does well in small groupings or foundation plantings. Tulips, on the other hand, are very formal and look best when planted in clumps or beds of one color. Hyacinths are so stately that a few plants carefully placed will provide colorful spring interest and fragrance.

Rhonda says to buy your bulbs early while the selection is good. Although late October is the best time to plant bulbs, anytime now will do. The ideal planting time is about four weeks before the ground freezes. This allows the bulb to grow some roots before winter. Select bulbs that are firm and free from soft or rotting spots or other signs of disease. Bulbs do best in well-drained soil. If your soil has a high clay content, the drainage can be improved by adding composts, peat moss, or other organic material.
To encourage root development this fall, many gardeners add phosphorus at planting time. The most common way to do this is to sprinkle a teaspoon of bonemeal in the bottom of each hole, cover it with a little soil, and then place the bulb. You can also fertilize the shoots as soon as they break through the soil in the spring. Do not fertilize bulbs after they have started flowering.
According to Rhonda, the most important part of bulb planting is proper depth. As a rule of thumb, plant the bulb two to three times as deep as it is wide. Large bulbs such as tulips and daffodils will be planted about 8 inches deep and smaller bulbs like crocus will be planted 3 to 4 inches deep. Measure planting depth from the bottom of the bulb. Bulbs should be planted with the nose of the bulb upward and the basal or root plate down. Special tools such as bulb augurs for the drill and hand diggers are available. Use these if they work better for you, but many prefer to simply dig individual holes with a hand trowel.
On another note, now is also the time to bring in the tender flowering “bulbs” for winter storage. Tender flowering bulbs include dahlias, gladiolas, cannas, tuberous begonias, and caladiums. These plants require special care since freezing temperatures kills them, but can be stored for replanting next year.
For more information on this or other horticultural issues, contact your local Extension office by visiting www.extension.illinois.edu. You can also post questions on Rhonda’s facebook page at www.facebook.com/ferree.horticulture.

Rhonda Ferree, Extension Educator in horticulture, says that trees can take three to five years to show symptoms from a severe event such as drought. Unfortunately trees under stress are less able to fight off insect and disease problems. Plant diagnosticians at the University of Illinois Plant Clinic describe the following diseases that take advantage of trees under stress.

Canker diseases are fairly common on stressed honey locust trees. Research has shown that honey locust cultivars vary in susceptibility to the canker fungi. Look for resistance ratings when purchasing new honey locust trees. The disease has been linked to drought stress in many cases. Where tree selection is not a choice, avoid injury, provide water in periods of drought stress, and help tree vitality by removing dead wood and fertilizing in the spring. As with most canker diseases, there is no rescue treatment that can be sprayed on the tree. When you see a canker problem, try to determine the cause of stress and take measures to alleviate that stress.

Drought-stressed elm trees are more attractive to the elm bark beetle, which may carry the Dutch elm disease fungus. With Dutch elm disease you will want to watch for yellowing of the leaves, followed by wilting and browning. Often this happens so quickly that the problem is first noticed when branches with brown leaves appear in the canopy seemingly overnight. It is generally too late to save a tree once it is infected, but an accurate diagnosis of the problem may help save nearby elm trees.

Pines under drought stress lack the ability to make resins to protect against pinewood nematodes and pine wilt disease. Pine wilt symptoms to watch for are gray-green foliage or needles that appear dull or off-color. The tree will not improve. Instead, as the summer progresses, the foliage will turn yellow and then brown and remain attached for a long time. Pine wilt occurs on any of the pines we grow in Illinois except for white pine. There is no cure for a tree infested with pinewood nematodes. Trees confirmed to be infected trees should be removed as soon as possible. Debris from the infested tree should be removed and burned or buried.

Symptoms of Verticillium wilt are more pronounced in drought, in part because drought inhibits the trees ability to wall off the fungus. Symptoms include wilt, branch death, and quick decline of plants. Hundreds of plant species, including trees, shrubs, groundcovers, vines, vegetables, fruits, herbaceous ornamentals, and flowers may become infected. Some trees that are frequently infected by this disease are maple, ash, and elm. There is no cure for Verticillium wilt.

I first wrote about garlic mustard in 2001. Since then, this dreadful weed has gotten even worse. Many hundreds of man-hours and dollars have been spent trying to prevent it from choking out more of our native wildflowers.

Garlic mustard, Alliaria petiolata, is not a weed to take lightly; if you have it, control is imperative.

In Illinois, the plant behaves mostly as a biennial. After germinating in the spring, the plant spends its first summer and winter as a rosette of heart-shaped leaves (2-8” long) with coarse, round, irregular teeth on the margins. The following spring, the plants send up a 1-2 foot flowering stalk of small, four-petaled, white flower clusters.

The plant spreads exclusively by seed on the fur of larger animals such as deer, by flowing water, and by human activities. The Illinois Invasive Species Awareness blog at www.illinoisisam.blogspot.com reported in March 2014 that excessive deer populations actually facilitate the garlic mustard invasion.

Seeds disperse when the seedpods burst at maturity in August. Seeds have a 20-month dormancy period and do not germinate until the second spring after ripening. Some plants produce as many as 8,000 seeds! Therefore, the goal of any garlic mustard control program is to prevent seed production until the seed bank is exhausted, usually a two to five-year period. I cannot emphasize the importance of not letting this plant go to seed!

In 2001 I naively thought I could keep ahead of the garlic mustard invasion on my own property by pulling any plants I found. It didn’t take long, however, for the hostile weed to win that battle. Our woods are now covered with it!

If you have the time, removal of plants by hand pulling is effective if the root is removed. If the stem snaps off from the root crown of a non-flowering plant, the plant may resprout. Other methods of control include spring burning, cutting flowering stems with a scythe, and herbicides.

The only possible positive of this invasion is that garlic mustard is edible. As the name says, it is a plant in the mustard family with a slight garlic taste. I’ve used it to make pesto.

“Great Garlic Mustard Hunts” are now held to ensure that this disruptive plant does not overcome our forests. In April and May 2011, the East Central Illinois Master Naturalists harvested 2,740 pounds of garlic mustard. Their hunt was copped off with a celebration and potluck featuring garlic mustard recipes!

Time for our next gardening trend of 2014: Young Men Get Down and Dirty. According to the 2014 Garden Media Group report, men aged 18 -34 are spending $100 more than the average gardener. They are grilling, growing their own hops for beer, and taking the kids out to play in the dirt. All good things!

Hops (Humulus lupulus) is an herbaceous perennial vine that grows well in central Illinois – sometimes too well. It is a very vigorous vine that can grow 20 to 30 feet long. Ideally a strong trellis is used to support the vine. In Jamaica I saw hops growing commercially on large pergola-type structures. Closer to home I’ve seen it growing up the back of a garage, along fences, and sprawling along the ground.

Brewing craft beers at home is a growing trend. The basic ingredients of beer are water, a starch source such as wheat or barley, a brewer’s yeast, and a flavoring such as hops. Personally I am not a fan of “hoppy” beer, but it is very popular.

The part of the plant that is used to brew beer is the cone from the female plant. Female plants will produce seedless cones without a male plant nearby, which works fine for brewing beer.

Since you want a female plant do not start hops from seed in your garden. Instead purchase female potted plants or rhizomes (roots) to plant in the garden. The plant prefers a sunny location with well-drained soil, though it does tolerate some dryness.

I planted a hops vine this spring in my herb garden. In addition to beer, the female hop cone is also used to make tea. One hops plant will yield about one to two pounds of dried cones in early- to mid-fall. Cones are ripe when they feel dry, papery, and leaves are scented. Dry cones can be stored in air-tight containers or in the freezer until use.

Nugget and Cascade are popular hops varieties with home brewers. Nugget is considered a bitter hop that stores well, though it is late to mature. Cascade is considered an aroma type that matures early with a floral and spicy aroma.

Hops are also grown as an ornamental vine. A popular variety for this use is ‘Aureus.’ It’s maple-like leaves are a luminous, clear shade of yellow.

Obviously you don’t have to be an 18-34 year old male to grow hops. Whether you grow it as an ornamental or to use when brewing beer, hops is a great addition to many gardens.